The invention relates to a diagnostic radiology system for angiography x-ray examinations, comprising an image intensifier television chain and an image subtraction device connected thereto with at least one image memory whose image data is subtracted from image data which occurs at other times than the stored image data, and comprising a display unit for displaying the subtraction images, in which a control device for controlling image processing is present.
A diagnostic radiology system of this type is described for example, in an article from the conference publication IEEE Catalog No. 76CH 1160-1C, 1976, pages 255-260. This article relates to enhancement of an angiocardiographic image-series by digital processing methods. It is possible here to store in the image memory one radiograph, or image data based on several integrated radiographs which represents a contrast-medium-free cardiovascular image of the radiography subject, and to form a difference image from this stored image data and later image data which corresponds to the same region of the radiography subject after an x-ray contrast agent is introduced into the blood vessels. In this manner, a fluoroscopic image can be obtained in real time which shows only the blood vessels important for the diagnosis which are filled with contrast medium. It is also possible to record the image scene to be examined with the aid of a video recorder and to conduct the image subtraction on the basis of the recorded scene.